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Transformer 3-Phase Current Formula:
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The 3-phase transformer current formula calculates the current (I) in amperes for a three-phase transformer system based on the power rating in kilovolt-amps (KVA) and the voltage (V) in volts. This calculation is essential for proper transformer sizing and electrical system design.
The calculator uses the 3-phase current formula:
Where:
Explanation: The formula converts KVA to volt-amps (by multiplying by 1000), then divides by the product of voltage and the square root of 3 to calculate the current in a balanced 3-phase system.
Details: Accurate current calculation is crucial for proper transformer selection, circuit breaker sizing, conductor sizing, and ensuring electrical system safety and efficiency in three-phase power systems.
Tips: Enter the transformer KVA rating and system voltage in volts. Both values must be positive numbers. The calculator will compute the current in amperes for a balanced 3-phase system.
Q1: Why is the √3 factor used in 3-phase calculations?
A: The √3 factor accounts for the phase difference in three-phase systems where the voltage between phases is √3 times the phase-to-neutral voltage.
Q2: What is the difference between KVA and KW in transformer ratings?
A: KVA represents apparent power (voltage × current), while KW represents real power (actual work done). Transformer ratings are typically in KVA because they must handle both real and reactive power.
Q3: Can this formula be used for single-phase systems?
A: No, for single-phase systems, use I = KVA × 1000 / V (without the √3 factor).
Q4: What are typical voltage values for 3-phase systems?
A: Common voltages include 208V, 240V, 480V, 600V, and higher voltages for industrial applications. Always verify the specific system voltage.
Q5: How does power factor affect current calculations?
A: This formula calculates apparent current. For real current (considering power factor), use I = KW × 1000 / (V × √3 × PF) where PF is the power factor.